1. Field of the Invention
This invention relates generally to animal surgical procedures, and more particularly to a process for removing one or more claws of domesticated cats.
2. Description of the Related Art
For the purpose of medical necessity, due to trauma or infection, or because of owner election, the claws of felines, and most commonly household cats, are frequently removed. It is the second most performed elective procedure next to sterilization and practiced by veterinarians worldwide.
Onychectomy is the disarticulation and removal of the third phalanx in cats. Conventionally, onychectomy has been performed using mechanical cutting instruments, such as scalpels and clippers, to sever the skin, ligaments, tendons, and synovium at the PII-PIII joint. The instruments mechanically sever all of the tissue along a transverse plane passing between the second and third phalanges (PII-PIII) in the manner of a guillotine. Conventional onychectomy procedures cause complications due to the nature of the instruments used. The complications are hemorrhage, pain, swelling and tissue deficit due to removal of PIII. The tissue deficit is generally closed with sutures or tissue adhesives.
The complications of hemorrhage, pain and swelling have been reduced with the introduction of the CO2 surgical laser. Exposure of the laser beam to tissue excites water molecules within tissue cells. The energy of the laser vaporizes the water in the cells and thereby ruptures the cells. The laser causes minimal damage to adjacent cells due to the fact that the beam is so narrow. Vaporization of cells coagulates small blood vessels and resects nerves with minimal trauma.
Although laser onychectomy reduces hemorrhaging, pain and swelling, traditional laser techniques retain the guillotine-oriented cutting path, thereby resulting in tissue deficit at the site where the third phalanx is removed. This deficit necessitates epidermal closure to cover the surgical site. As previously stated, this involves suturing the epidermis or closing it with tissue adhesive. Frequently no closure is used and the deficit closes by secondary intention resulting in delayed healing and the increased possibility of infection.
The invention is a feline onychectomy surgical method using a laser cutting instrument. The method removes the third phalanx with reduced bleeding, pain and swelling by strict anatomical dissection of only connective tissue structures. Most importantly, the technique leaves a substantial portion of tissue to cover the exposed tip of the second phalanx. This eliminates the need for surgical closure of the remaining epidermis and decreases the incidence of infection.
The method includes forming a first circumferential incision with the laser in the epidermis at the edge of the ungual crest of the feline""s claw. This first incision severs the most distal portion of the epidermis from the underlying fascia of the ungual crest. After the first incision, the surgeon applies cranial traction to the epidermis severed from the ungual crest to displace the distal edge of the epidermis cranially.
A second circumferential incision is preferably formed in the epidermis about 3 millimeters cranial to the first circumferential incision. This distance can vary, depending upon the size of the feline, but 3 millimeters is common for the domesticated cat. This second incision extends deeper into the subcutaneous fascia and further facilitates the cranial displacement of the epidermis from the ungual crest.
After making the second incision, the epidermis is pushed cranially and the extensor tendon is incised near its insertion on the ungual crest. This incision is formed by directing the laser beam in a substantially palmar direction when a laser beam source is positioned substantially dorsally of the extensor tendon. Next, the synovium of the PII-PIII joint is incised and traction is applied to the claw in the palmar direction to begin to disarticulate the PII-PIII joint and allow access to the medial and lateral collateral ligaments.
The medial and lateral collateral ligaments are ablated by directing the laser beam in a substantially palmar direction when the laser source is positioned substantially dorsally of the ligaments. This allows further disarticulation of the PII-PIII joint and access to the digital flexor tendon by palmar rotation of PIII. Next, the digital flexor tendon is incised by directing the laser beam in a substantially palmar direction when the laser source is positioned substantially dorsally of the flexor tendon. This allows for extreme palmar rotation of PIII and reveals the subcutaneous tissues of the pad.
Finally, the subcutaneous tissues of the pad of the second phalanx are incised by directing the laser beam in a substantially palmar direction when the laser source is positioned substantially dorsally of the subcutaneous tissues of the pad of the second phalanx.
The invention involves resection of the redundant epidermis to allow complete anatomical dissection and removal of the claw from a strictly cranio-dorsal approach. By operating only from the dorsal part of the paw and anatomically dissecting PIII by vaporizing only the connective tissue structures, trauma to the surrounding tissue is minimized. The preserved epidermis of the ungual crest that is normally discarded by all other techniques is retained to cover virtually all of the surgical site.
Of course, this surgical process will be recognized by a person having ordinary skill in the art to be adaptable to other animals, specifically dogs.